To help avoid constraints to external objects, what selection scope can be used while working in a sketch?

Choosing "Within active sketch only" as the selection scope while working in a sketch is advantageous because it restricts the focus solely to the elements present in that specific sketch. This helps eliminate any potential constraints that could inadvertently reference external objects or sketches, which could complicate design modifications or lead to unexpected behavior in the model.

By concentrating on the geometry within the active sketch, designers can freely create the intended shapes without the interference of other existing sketches, features, or assembly components that might lead to complex relationships. This targeted approach allows for clearer design intentions and simplifies the constraint management process, making it easier to define relationships solely relevant to the current sketch.

The other selection scopes involve broader selections which could include other sketches, features, or the entire assembly, creating the risk of inadvertently linking or constraining to elements outside the intended design, thereby complicating the workflow and increasing the chances of errors.